1. Field of the Invention
The disclosures herein generally relate to a recording medium placement device and an image forming apparatus.
2. Description of the Related Art
An image forming apparatus such as a copy machine or a facsimile machine is provided with a paper placement device in which a paper is placed, as a recording medium placement device in which a recording medium is placed. That is, for example, it is provided with a paper feed cassette in which a print paper is placed or a manuscript tray in which a read manuscript is set. These paper placement devices include movable opposing guide members (side fence) in order to prevent a print failure or a paper feed failure arising from an irregularity of the placed paper (print paper or read manuscript).
These guide members are configured so as to move by the same distance in conjunction with each other in opposite directions to each other along a width direction of the paper (a direction orthogonal to a paper feed direction or a transportation direction). Manual type guide members which are moved by a user manually are common. But, automated guide members so as to simplify the user's operation are also known. That is, Japanese Patent No. 3969215 describes controlling so that two guide members are moved in directions to approach each other automatically from initial positions when a manuscript is placed and the guide members are stopped when the guide members contact the paper.
However, the automatic control of guide members described in Japanese Patent No. 3969215 is control where contact of the guide members with the paper is detected and the guide members are stopped immediately. Accordingly, the automatic control of guide members in Japanese Patent No. 3969215 has a problem that a positional relationship of the paper and the guide members may not be appropriate due to a detection error of a detection mechanism for the contact of the guide members with the paper, by which a difference in the stop positions of the guide members between devices may occur.
That is, the positional relationship becomes a remote positional relationship where a gap appears between the paper and the guide members or a too close positional relationship where the paper is held between the guide members and is deflected.